GENEVA (MCT) — Secretary of State John Kerry broke off a Middle East trip Friday and flew to Geneva to push negotiations with Iran on a diplomatic framework that would prevent Tehran from using the enriched uranium it has been busy producing to produce a nuclear weapon.

Kerry arrived from Tel Aviv, after a highly contentious encounter with Prime Minister Benjamin Netanyahu. The Israeli leader said he "utterly rejects" what he called "a very bad deal" with Iran.

"This is a very bad deal and Israel utterly rejects it. Israel is not obliged by this agreement and Israel will do everything it needs to do to defend itself and defend the security of its people," he said. Kerry did not comment.

But on arriving in Geneva, Kerry cautioned that no deal had been concluded and said his aim in traveling here was to "see if we could narrow the differences."

"I want to emphasize that there still are very important issues on the table that are unresolved. It's important that those be thoroughly addressed," he said. "There is no agreement at this time."

The foreign ministers of France, Britain and Germany also flew to Geneva, leaving only Russia and China without ministerial level representation in the talks. The first to arrive was minister Laurent Fabius, representing a French government that had made the toughest demands on that Iran curb its uranium enrichment program.

Fabius said on arrival that "nothing so far has been finalized."

"I have come personally to Geneva because these are negotiations that are difficult but important for the regional and international security," Fabius said on arrival. "It is a question of reaching an agreement which represents a first solid step in addressing the international concerns over the Iranian nuclear program."

Jen Psaki, the State Department spokeswoman, said Kerry had come to Geneva to help narrow the differences in negotiations at the request of Catherine Ashton, the European Union's foreign policy chief, who heads the six-nation delegation negotiating with Iran.

Reporters on Kerry's plane were hold that he was to meet with Undersecretary of State Wendy Sherman, the chief U.S. negotiator, then see Ashton, followed by a meeting Fabius. Then he would hold a meeting with Ashton and the Iranian foreign minister, Javad Zarif.

The deal under discussion would lift some of the extensive international economic sanctions imposed on Iran in exchange for Iran agreeing to curb its nuclear enrichment program that already has produced an enormous stockpile of low enriched uranium and some 200 kilograms (440 pounds) of uranium enriched to 25 per cent purity, only a few steps short of acquiring the 90 percent pure uranium that would be needed for a nuclear weapon.

The understanding likely to be signed Friday would include so-called confidence building measures that would allow the United States and its allies to monitor Iranian cooperation and improve the atmosphere for negotiations leading to a final resolution of the dispute.

Zarif said Thursday that the drafting of the agreement could begin Friday morning and could be completed by the scheduled end of the talks Friday afternoon.

It would be the first international accord to restrain Iran's nuclear program in over a decade, but so little was known about the details that it was difficult for outsiders to form a judgment on whether the deal genuinely would represent genuine progress.

But Netanyahu indicated that he was aware of the content of the agreement, and made clear that he found it completely unacceptable.

"I understand the Iranians are walking around very satisfied in Geneva, as well they should because they got everything and paid nothing," Netanyahu told reporters before meeting Kerry.

"They wanted relief of sanctions after years of grueling sanctions, they got that," he said of Iran. "They paid nothing because they are not reducing in any way their nuclear enrichment capability. So Iran got the deal of the century and the international community got a bad deal," he said.

Netanyahu's outburst was an almost unprecedented public break with the U.S. government and portends a vigorous campaign by Israel and its supporters in Congress for new and far tougher sanctions against Iran. The House has already approved them, but the Senate appears divided.

Netanyahu appears determined to try to thwart the accord.

He told the Washington Post that the proposed accord was a "monumental mistake."

"There's no earthly reason to do this," he said. "Not only the force of the existing sanctions but the threat of the future sanctions was the great impetus on the mind of Khamenei, and now they could just take that away." He was referring to Iran's supreme leader, Ayatollah Ali Khamenei, the ultimate arbiter of policy in Iran.